Table of Contents
- 1 What should be the condition for the efficiency of a Carnot engine to be equal to 1?
- 2 What is the formula for efficiency of Carnot engine?
- 3 What is the value of efficiency of the engine T2?
- 4 Is the efficiency of Carnot engine 1?
- 5 How do you calculate work done by a heat engine?
- 6 Why can COP be greater than 1?
- 7 What is the proof of Carnot theorem?
- 8 What does T1-T2 =0\% efficiency mean?
What should be the condition for the efficiency of a Carnot engine to be equal to 1?
Thus, for or η = 1 , W = Q 1 or Q 2 = 0 , the total heat which is abstracted from the source gets converted into work.
What is the formula for efficiency of Carnot engine?
efficiency =WQH=1−TCTH. These temperatures are of course in degrees Kelvin, so for example the efficiency of a Carnot engine having a hot reservoir of boiling water and a cold reservoir ice cold water will be 1−(273/373)=0.27, just over a quarter of the heat energy is transformed into useful work.
How do you find the heat rejected by a Carnot engine?
To find the work done, use the formula giving relation between work done, efficiency and heat absorbed. Substitute the values and obtain the amount of work done. Now, subtract the heat absorbed from the work done. This will give the amount of heat rejected per cycle.
What is the relation between COP of heat pump and efficiency of heat engine?
The coefficient of performance or COP (sometimes CP or CoP) of a heat pump, refrigerator or air conditioning system is a ratio of useful heating or cooling provided to work (energy) required. Higher COPs equate to higher efficiency, lower energy (power) consumption and thus lower operating costs.
What is the value of efficiency of the engine T2?
A Carnot engine operating between temperatures T1 and T2 has efficiency 0.2. When T2 is reduced by 60 K, its efficiency increases to 0.4.
Is the efficiency of Carnot engine 1?
When the temperature of the sink is reduced by 62oC, its efficiency is doubled. The temperatures of the source and the sink are, respectively.
What is the Carnot efficiency of a heat engine?
The Carnot Efficiency is the theoretical maximum efficiency one can get when the heat engine is operating between two temperatures: The temperature at which the high temperature reservoir operates ( THot ). The temperature at which the low temperature reservoir operates ( TCold ).
How do you calculate heat rejection?
Total heat of rejection (THR) is equal to net refrigeration effect (RE) at the evaporator (compressor capacity) plus the energy input into the refrigerant by the compressor (heat of compression).
How do you calculate work done by a heat engine?
The useful work done by a heat engine is W = Q1 – Q2 (energy conservation). An ideal reversible engine does the maximum amount of work. Any real engine delivers more heat Q2 at the reservoir at T2 than a reversible one and therefore does less useful work.
Why can COP be greater than 1?
This means the COP of Heat Pumps is always greather than 1 and is therefore is a ratio of performance, not a ratio of efficiency, because a machine with an efficiency greater than 1 would imply that the machine is creating something out of nothing, which is impossible.
What is the relation between COP of refrigerator and COP of heat pump?
ANSWER: [COP]H.P. = 1 + [COP]ref In refrigerator, the desired effect is to maintain temperature of the body A lower than the surrounding temperature.
What is the efficiency of a Carnot heat engine?
The efficiency of a Carnot heat engine is given by the Formula: 1 – T2/T1, which has been derived above. Thus the efficiency will completely depend on the temperatures of the source and the sink and is not a constant, However for a given set of source temperature and sink temperature the Carnot heat engine is the most efficient engine possible.
What is the proof of Carnot theorem?
Carnot Engine: Proof of Carnot Theorem… “It is impossible for any heat engine to be more efficient than a Carnot engine when operating between two given temperatures”. The Carnot engine is a conceptual engine that achieves the most efficient conversion of heat to work permitted by Kelvin’s statement.
What does T1-T2 =0\% efficiency mean?
Where T2 & Q2 are temperature and heat energy at sink. If T1=T2, then T1-T2 =0, which means 0\% efficiency. The flow of heat requires a temperature gradient between source and sink.
What is the use of a Carnot engine?
Carnot engine is a theoretical thermodynamic cycle proposed by Leonard Carnot. It gives the estimate of the maximum possible efficiency that a heat engine during the conversion process of heat into work and conversely, working between two reservoirs, can possess.